<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>计算器练习</title>
</head>
<body>
    <input type="text" id="i1">
    <input type="text" id="i2">
    <input type="button" value="加" onclick="f1()">
    <input type="button" value="减" onclick="f2()">
    <input type="button" value="乘" onclick="f3()">
    <input type="button" value="除" onclick="f4()">
    <h2>结果:<span></span></h2>
    <script>
        // 获取文本框
        let i1 = document.querySelector("#i1")
        let i2 = document.querySelector("#i2")
        // 获取span
        let s = document.querySelector("span")
        function f1(){
            s.innerText = i1.value*1+i2.value*1;
        }
        function f2(){
            s.innerText = i1.value - i2.value;
        }
        function f3(){
            s.innerText = i1.value * i2.value;
        }
        function f4(){
            s.innerText = i1.value / i2.value;
        }
    </script>
</body>
</html>